1. Field of the Invention
The present invention relates to a tuning device.
2. Description of the Related Art
Up to now, there are known tuning devices configured to perform tuning by using pitch information of an arbitrary input sound as a reference. FIG. 11 illustrates a structure of a conventional tuning device 400. A microphone 401 and a vibration sensor 405 each sample a sound emitted from a musical instrument, and convert the sound into an electrical signal. An amplifier 402 receives an output signal from at least one of the microphone 401 and the vibration sensor 405, and amplifies the electrical signal to a desired level. A CPU 403 includes pitch extracting means for receiving an output signal from the amplifier 402 and extracting from the output signal a fundamental period of the sound sampled by at least one of the microphone 401 and the vibration sensor 405. In addition, the CPU 403 includes reference sound setting means, by which a user presets a reference sound. The CPU 403 further includes pitch error detecting means, by which an output from the pitch extracting means and an output from the reference sound setting means are received to calculate a pitch error therebetween and then output a result thereof to display means 404. The display means 404 visually displays a pitch difference between the reference sound and the sound emitted from the musical instrument to be tuned. It is called a “tuning function” of the tuning device to indicate an index during the tuning of the musical instrument with the above-mentioned structure.
Note that as the vibration sensor 405, a compact part such as a piezoelectric element is used. As the pitch extracting means, instructions such as “measure the period of a fundamental wave component having the longest period in the input signal” are stored in a memory of the CPU 403. In a similar manner, as the pitch error detecting means, instructions such as “calculate the frequency difference between the input signals” are stored in the memory of the CPU 403. The amplifier 402, the memory, and the like are mounted on a circuit board, which is contained inside a main body of the tuning device. The reference sound setting means is constituted by a switch and the like. The display means 404 is constituted by a meter, an LCD, a combination of a plurality of LEDs, and the like. FIG. 12 illustrates an external appearance of a general tuning device.
Before placing a conventional tuning device, it is necessary to search for a place in which the tuning device may efficiently sense the sound emitted from the musical instrument to be tuned. In tuning a brass instrument, a sound emitting side in the vicinity of a bell thereof is the most efficient position for sampling the sound. However, placing the tuning device in the above-mentioned position raises a problem in that the bell conceals a display surface from view. In order to solve such a problem, there is proposed a tuning device equipped with a pivotable joint between a clip portion for pinching the vicinity of a sound emitting portion of the musical instrument and the display surface for displaying a result of the tuning thereon, which may be located in a position that makes it easy for a player to visually recognize the display surface (see, for example, JP 2003-255932 A).
Incidentally, in the tuning device disclosed in JP 2003-255932 A, wirings are used to connect the vibration sensor attached to the clip portion and the circuit board disposed inside the display portion with each other, and when the display portion is caused to pivot, the wirings arranged inside the joint are caused to pivot together, which may result in the twisted wirings. This leads to a problem that the wirings are broken in a short period of time. Therefore, there is proposed a tuning device having the vibration sensor provided to the display portion side instead of the clip portion. However, such a structure makes it difficult for the vibration sensor to sense the sound, leading to a problem that performance as the tuning device may be lowered.